To automatically extract libels and slanders against a company from information disclosed in the Internet has been conducted by using some document searching tools hitherto. However, a method is adopted in which keywords are specified and a patrol of Web pages is made to extract them by using the specified keywords, or URLs (Uniform Resource Locator) of search objects are specified in advance to extract, them. That is, such a judgment that the collected information is information of a good evaluation or information of a bad evaluation is not made. Further, information as to the influence of the collected information cannot also be obtained. Thus, it is not suitable for finding “circulation of rumor” for stock price manipulation.
U.S. Pat. No. 6,438,632 discloses an electronic bulletin board system having a function of automatically checking the contents of a message transmitted from a user computer and desired to be presented on the electronic bulletin board. That is, with respect to the message transmitted from the user computer and desired to be presented on the electronic bulletin board, a check is made according to a glossary of presentation-inhibited words, which includes words previously selected as being unsuitable for presentation on the electronic bulletin board. In the case where any word in the glossary of presentation-inhibited words is not included in the message desired to be presented, the message is presented on the electronic bulletin board. On the other hand, in the case where any word in the glossary of presentation-inhibited words is included, a notice that the message cannot be presented is given to the user computer. Besides, at this time, the event of rejecting the presentation of the message is notified to an operation administrator computer. In such a technique, although it is possible to judge the permission or inhibition of the presentation on the bulletin board, the contents of a message judged to be capable of being presented cannot be automatically analyzed.
As stated above, according to the conventional technique, although definitely specified information can be extracted from an enormous amount of information, noticeable information cannot be automatically extracted, and the interpretation and analysis of the extracted information must be manually made. Thus, the user cannot obtain the characteristics of the extracted information, the source of the information, and the like without a further operation.